MQL4 Reference Constants, Enumerations and Structures Named Constants Numerical Type Constants

Numerical Type Constants

Each simple numerical type is intended for a certain type of tasks and allows optimizing the operation of a mql4-program when used correctly. For a better code readability and correct handling of calculation results, there are constants which allow to receive information about restrictions set to a certain type of simple data.

Constant	Description	Value
CHAR_MIN	Minimal value, which can be represented by char type	-128
CHAR_MAX	Maximal value, which can be represented by char type	127
UCHAR_MAX	Maximal value, which can be represented by uchar type	255
SHORT_MIN	Minimal value, which can be represented by short type	-32768
SHORT_MAX	Maximal value, which can be represented by short type	32767
USHORT_MAX	Maximal value, which can be represented by ushort type	65535
INT_MIN	Minimal value, which can be represented by int type	-2147483648
INT_MAX	Maximal value, which can be represented by int type	2147483647
UINT_MAX	Maximal value, which can be represented by uint type	4294967295
LONG_MIN	Minimal value, which can be represented by long type	-9223372036854775808
LONG_MAX	Maximal value, which can be represented by long type	9223372036854775807
ULONG_MAX	Maximal value, which can be represented by ulong type	18446744073709551615
DBL_MIN	Minimal positive value, which can be represented by double type	2.2250738585072014e-308
DBL_MAX	Maximal value, which can be represented by double type	1.7976931348623158e+308
DBL_EPSILON	Minimal value, which satisfies the condition: 1.0+DBL_EPSILON != 1.0 (for double type)	2.2204460492503131e-016
DBL_DIG	Number of significant decimal digits for double type	15
DBL_MANT_DIG	Number of bits in a mantissa for double type	53
DBL_MAX_10_EXP	Maximal decimal value of exponent degree for double type	308
DBL_MAX_EXP	Maximal binary value of exponent degree for double type	1024
DBL_MIN_10_EXP	Minimal decimal value of exponent degree for double type	(-307)
DBL_MIN_EXP	Minimal binary value of exponent degree for double type	(-1021)
FLT_MIN	Minimal positive value, which can be represented by float type	1.175494351e-38
FLT_MAX	Maximal value, which can be represented by float type	3.402823466e+38
FLT_EPSILON	Minimal value, which satisfies the condition: 1.0+DBL_EPSILON != 1.0 (for float type)	1.192092896e—07
FLT_DIG	Number of significant decimal digits for float type	6
FLT_MANT_DIG	Number of bits in a mantissa for float type	24
FLT_MAX_10_EXP	Maximal decimal value of exponent degree for float type	38
FLT_MAX_EXP	Maximal binary value of exponent degree for float type	128
FLT_MIN_10_EXP	Minimal decimal value of exponent degree for float type	-37
FLT_MIN_EXP	Minimal binary value of exponent degree for float type	(-125)

Example:

void OnStart()
  {
//--- print the constant values
   printf("CHAR_MIN = %d",CHAR_MIN);
   printf("CHAR_MAX = %d",CHAR_MAX);
   printf("UCHAR_MAX = %d",UCHAR_MAX);
   printf("SHORT_MIN = %d",SHORT_MIN);
   printf("SHORT_MAX = %d",SHORT_MAX);
   printf("USHORT_MAX = %d",USHORT_MAX);
   printf("INT_MIN = %d",INT_MIN);
   printf("INT_MAX = %d",INT_MAX);
   printf("UINT_MAX = %u",UINT_MAX);
   printf("LONG_MIN = %I64d",LONG_MIN);
   printf("LONG_MAX = %I64d",LONG_MAX);
   printf("ULONG_MAX = %I64u",ULONG_MAX);
   printf("EMPTY_VALUE = %.16e",EMPTY_VALUE);
   printf("DBL_MIN = %.16e",DBL_MIN);
   printf("DBL_MAX = %.16e",DBL_MAX);
   printf("DBL_EPSILON = %.16e",DBL_EPSILON);
   printf("DBL_DIG = %d",DBL_DIG);
   printf("DBL_MANT_DIG = %d",DBL_MANT_DIG);
   printf("DBL_MAX_10_EXP =  %d",DBL_MAX_10_EXP);
   printf("DBL_MAX_EXP = %d",DBL_MAX_EXP);
   printf("DBL_MIN_10_EXP = %d",DBL_MIN_10_EXP);
   printf("DBL_MIN_EXP = %d",DBL_MIN_EXP);
   printf("FLT_MIN = %.8e",FLT_MIN);
   printf("FLT_MAX = %.8e",FLT_MAX);
   printf("FLT_EPSILON = %.8e",FLT_EPSILON);
  }

Mathematical ConstantsUninitialization Reason Codes